Ladder for evacuating persons from chair aerial cable lifts

ABSTRACT

A ladder for evacuating persons from chair aerial cable lifts comprising, a rigid ladder, an elongate hook support member, means for securing the lower end of the hook support member to at least one ladder rung and a hook which is substantially U-shaped in cross section attached to the upper end of the support member, the hook comprising an elongate outer end member and two spaced side members which combine to form a groove adapted to receive the cable of a lift, the longitudinal centerline of the groove extending substantially normal to the longitudinal centerlines of the rungs of the ladder when viewed from the top to cause the rungs of the ladder to be positioned substantially parallel to the front or forward end of a chair suspended from the cable and also to aid in preventing twisting of the ladder relative to the cable in use. In a preferred embodiment, a pair of semielliptical grooves are provided in the outer end member, one at each end thereof. In another preferred embodiment, the hook also comprises latch means for releasably closing the groove at a locality spaced below the elongate outer end member of the hook.

United States Patent 1191 Wallingford 211 App]. No.: 301,055

[52] US. Cl. 182/206 [51] Int. Cl. E066: 1/36, E06c 7/48 [58] Field ofSearch...... 182/206, 214;

[56] References Cited UNITED STATES PATENTS 526,438 9/1894 Croissant182/38 246,658 9/1881 182/206 283.530 8/1883 Swartz 182/206 2,316,7234/1943 Sorensen 182/206 2,903,086 9 1959 Chubbs 182/214 PrimaryExaminerReinaldo P. Machado Attorney-C. Yardley Chittick et al.

[ Dec. 25, 1973 [5 7] ABSTRACT A ladder for evacuating persons fromchair aerial cable lifts comprising, a rigid ladder, an elongate hooksupport member, means for securing the lower end of the hook supportmember to at least one ladder rung and a hook which is substantiallyU-shaped in cross section attached to the upper end of the supportmember, the hook comprising an elongate outer end member and two spacedside members which combine to form a groove adapted to receive the cableof a lift, the longitudinal centerline of the groove extendingsubstantially normal to the longitudinal centerlines of the rungs of theladder when viewed from the top to cause the rungs of the ladder to bepositioned substantially parallel to the front or forward end of a chairsuspended from the cable and also to aid in preventing twisting of theladder relative to the cable in use. In a preferred embodiment, a pairof semi-elliptical grooves are provided in the outer end member, one ateach end thereof. In another preferred embodiment, the hook alsocomprises latch means for releasably closing the groove at a localityspaced below the elongate outer end member of the hook.

9 Claims, 4 Drawing Figures l LADDER FOR EVACUATING PERSONS FROM CHAIRAERIAL CABLE LIFTS BACKGROUND OF THE INVENTION This invention relates toa ladder for evacuating persons from chair aerial cable lifts.

Chair aerial cable lifts are used extensively in the winter on skislopes. In use of such lifts, accidents occur making it necessary toevacuate a person from the chair of the lift to prevent injury or lossof life. In one case, a woman failed to properly seat herself on a chairand found herself dangling by one arm from the chair a short distancebeyond the loading platform and approximately feet in the air. Inanother case, a girl, intending to disembark at an intermediateunloading station on a chair lift, found herself suspended by her scarfwhich had become entangled with the chair. While in each case the liftwas stopped, serious problems of evacuating the persons from theirpredicaments were encountered and, inone case, ended in disaster.

While a common ladder may be erected from the snow-covered surface tothe aerial cable so that an attendant may try to ascend it and assistthe person to descend the ladder, this is unsatisfactory and dangerousbecause with the upper end of the ladder resting against the cable, therungs of the ladder are parallel to the cable and normal to the frontopening of the chair. This makes it difficult for the attendant toremove the person from the chair and difficult for the person to removehimself from the chair unassisted. Furthermore, with the legs of theladder resting upon a slippery, snow-covered surface, the ladder islikely to move while in use either by sliding along the ground or bytwisting relative to the cable and the chair.

Usually, there is only one attendant in attendance at the lift loadingor unloading area so the ladder used to evacuate the person from thechair should be capable of being erected and used very quickly by asingle attendant.

While the following United States patents disclose hooks for holdingladders upon buildings, they would not function satisfactorily for usein evacuating a person from a chair aerial cable lift:

Patent No. Date of Issue Inventor 143,112 Sept. 23, 1873 LE. Ainsworth246,658 Sept. 6, 1881 R. Bustin 312,908 Feb. 24, 1885 F. Shickle 526,438Sept. 5, 1894 M. Croissant 580,454 April 13, 1897 PJ. Gates 1,018,877Feb. 27, 1912 F.W. Chickering 1,036,482 Aug. 20, 1912 EA. Fredeen1,249,855 Dec. 11, 19l7 C.R. Taylor 1,252,224 Jan. 1, 1918 W.E. Bittner2,316,723 April 13, 1943 N.C. Sorenson In addition to the above patents,US. Pat. Nos. 2,963,104 dated Dec. 6, 1960 to Roth and 3,001,603 datedSept. 26, 1961 to Kraus disclose combined electrical conductor spreadersand ladder hangers but they would not function satisfactorily for use inevacuating a person from a chair aerial cable lift.

One object of this invention is to provide a novel ladder for evacuatinga person from chair aerial cable lifts.

Another object is to provide such a ladder which may be erected to anaerial cable adjacent to the chair quickly by a single attendant.

A further object is to provide such a ladder which, when erected,presents the rungs of the ladder substantially parallel to the front orforward end of the seat of the chair to facilitate evacuating a personfrom the chair.

A still further object is to provide such a ladder which does not twistrelative to the cable or the ground after it has been erected.

Another object is to provide such a ladder with a hook which permitsvariation of the angle of the ladder relative to the cable without lossof torsional support.

A further object is to provide such a ladder which includes a novel andefficient safety latch for use in fast erection of the ladder and inretaining the ladder in erected position during evacuation of a personfrom a chair lift.

Yet another object is to provide such a ladder with novel and efficientmeans for detachably and firmly securing a member which supports thehook to one or more rungs of a ladder so that the hook does not twist orturn relative to the ladder in use.

A still further object is to provide a novel ladder hook attachment foruse with a ladder for evacuating persons from chair or other aerialcable lifts.

Another object is to provide such a ladder hook attachment which isdurable, economical to manufacture and easy to install upon any rigidladder.

Other objects and advantages will be apparent to persons skilled in theart from the following description.

In its broadest aspect, the invention comprises a ladder having a pairof rigid side rails, a plurality of spaced rigid rungs extendingtransversely between said side rails, means for rigidly securing the.lower end of the hook support member to atleast one ladder rung, and ahook which is substantially U-shaped in cross section rigidly attachedto the upper end of the support member, the hook comprising an elongateouter end member and two spaced sidemembers which combine to form agroove adapted to receive the cable of an aerial lift, the longitudinalcenterline of the groove extending substantially normal to thelongitudinal centerlines of the rungs of the ladder when viewed from thetop. Consequently when the bottom of the groove is positioned upon thecable of an aerial lift the rungs of the ladder are positionedsubstantially normal to the longitudinal centerline of the aerial cablewhen viewed from the top and substantially parallel to the forward endof the seat of a chair suspended from the aerial cable.

In a preferred embodiment, the elongate outer end member comprises apair of semi-elliptical grooves, one at each end thereof.

In another preferred embodiment, the sides of the spaced side membersconverge as they extend downwardly from the elongate outer end member.

Preferably the book also comprises latch means for releasably openingand closing the groove at a locality spaced below the elongate outer endmember of the hook. This latch means may comprise an arm, one end ofwhich is pivotally attached to one side member of the hook, a toothmember attached to the other end of the arm and normally extendingtransversely of the groove to close it and an actuating member attachedto the other end of the arm and extending in the opposite direction fromthe tooth member. Spring means is provided which has one end attached tothe actuating member and the other end attached to one side member ofthe hook and this spring means normally biases the tooth member togroove closing position. A rope is attached to the actuatingmember formoving the arm about its pivotal connection to the side member,

whereby the toothmember may be moved from groove closing position toopen position to permit the hook to be quickly positioned about anaerial cable.

Preferably the means for securing the hook support member to a ladderrung comprises at least one U- shaped member bridging the rung anddetachably secured to the hook support member and an elongate anglemember positioned adjacent to the rung and between the legs of theU-shaped member.

From the foregoing description, it will be apparent to persons skilledin the art that this invention provides a ladder and a ladder hookattachment which satisfies the foregoing objects.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective showing anaerial cable and ski lift chair, a ladder embodying this invention inposition for evacuating a person from the chair and an extra ladder hungon the cable. support pole;

FIG. 2 is an enlarged section on the lines 2-2 of FIG. 1;

FIG. 3 is a section on the lines 3-3 of FIG. 2; and

FIG. 4 is a view in side elevation looking in the direction of thearrows 44 of FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, the pole supports theaerial cable 11. The chair 12 is shown in a position from which a person(not shown) may be evacuated from the chair by the use of a ladderembodying this invention. The rungs of the ladder are substantiallyparallel to the front or forward end of the seat of the chair andsubstantially normal to the longitudinal centerline of the cable.

The ladder consists of a pair of rigid side rails 14 and a plurality ofrigid rungs 15 extending transversely between the side rails. The laddermay be made of metal, wood, fiberglas, or the like.

The elongate hook support member 16, which may be made of aluminumtubing, is rigidly secured to the two uppermost rungs of the ladder.

The lower end of the hook support member 16 is rig idly secured to arung 15 by a pair of spaced. substantially paralle U-shaped members orbolts 17, the legs of which pass through orifices in a plate 18,orifices in the sides of the hook support member 16 and orifices in theplate 19. The apex of the angle member may be welded to the adjacentface of the plate 18. The rung 15 is positioned between the curved endsof the U- shaped members 17 and the sides of the angle member 20. Theangle member-may be about 12 inches long and the widths of the sides ofthe hook support member and the lengths of the plates 18 and 19 may beabout 2 inches. The U-shaped members 17 are detachably held in thepositions shown in FIGS. 2 and 3 by the nuts 22. The U-shaped membersmay be made of steel and the plates and angle member may be made ofalumi num.

The hook support member 16 is rigidly secured to the upper ladder rungby another pair of spaced, substantially parallel Ushaped members orbolts 24, the legs of which pass through orifices in the sides of thesupport member and orifices in the plate member 25. They are detachablyheld in position by the nuts 26. In this case, the periphery of the rung1S abuts the adjacent side of the support member 16 and the oppositeperiphcry of the rung is positioned against the sides of the anglemember 27, the apex of which is positioned against the curved ends ofthe U-shaped members 24.

In this case, the angle member 27 is also about 12 inches long so thatit engages the periphery of the rung 15 for a substantial length of therung.

Use of the plate 18 is unnecessary. In addition, an angle memberpositioned like the angle member 27 may be used with the U-bolts 17instead of using the angle member positioned at the opposite side of therung 15. Furthermore angle members positioned between the peripheries ofboth rungs and the adjacent side ofthe hook support member may be used.Other equivalent arrangements will be apparent to persons skilled in theart.

The hook, indicated generally by the numeral 30, may be made of highstrength cast aluminum alloy. It is substantially U-shaped inlongitudinal section as shown in FIG. 2. The hook shown in the drawingsis designed to receive an aerial cable 11 which is about 1% inches indiameter. For use with such a cable, the elongate outer end member 30Aof the hook may be about 4 inches long and the side members 308 and 30Cof the book may be about 6% inches long at the top and convergedownwardly to widths of about 2% inches when viewed from the side as inFIGS. 3 and 4 of the drawings. The end member 30A and side members 303and 30C of the hook form .a groove 31 which is adapted to receive thecable 11 of the ski chair lift as shown in FIG. 2. The end member 30A isprovided with semielliptical openings or grooves 30D which receive aportion of the cable when the ladder is tilted to the dotdash positionof FIG. 3.

The lower end of the side member 308 is rigidly secured to the upper endof the hook support member 16 by the bolt 33 which passes throughorifices in the support member and the side member 308 of the hook.

It is to be noted that the longitudinal centerline of the groove extendssubstantially normal to the longitudinal centerlines of the rungs 15 ofthe ladder when viewed from the top. This causes the rungs of the ladderto be positioned substantially normal to the longitudinal axis of thewhen viewed from the top cable and substantially parallel to the frontor forward end of the seat of the chair to aid in evacuating a personfrom the chair. It also tends to prevent twisting of the ladder relativeto the cable which is important when a person is being evacuated fromthe chair since frequently the lower ends of the ladder rest upon afrozen or snowy surface. The use of the elongate angle members 20 and 27also assist in preventing twisting of the hook member relative to therungs of the ladder.

The latch means, generally indicated by the numeral 40, comprises agenerally T-shaped member which includes an arm 41, a hook member 42 andan actuating member 43, The arm 41 is pivotally secured to a lug on themember 308 by a pin 44. The hook member 42 extends through a slot 45 inthe side member 303. A spring 47 has its upper end attached to the sidemember 308 by a bolt 48 and its lower end attached to the actuatingmember 43 by the bolt 49. This spring biases or urges the tooth memberto its groove closing position shown in FIG. 2 in which the end of thetooth abuts the inner side of the side member 30C.

The rope member 50 is attached to a ring 51 which passes through anorifice near the outer end of the actuating member 43. By pulling onthis rope the arm 41 may be moved clockwise (looking at FIG. 2) aboutthe pivotal connection 44 thereby moving the tooth member 42 out of thegroove 31 so that the hook may be placed over the cable 11 when theladder is to be used to evacuate a person from the chair. Upon releaseof the pulling force on the rope, the spring 47 returns the tooth memberto groove closing position where it remains until the ladder is to beremoved from the cable.

The ladder may be stored in vertical position when it is not in use byhanging it from a hook (not shown) on the cable support pole as shown inFIG. 1. Since the ladder is in upright position as thus stored, oneattendant may effect a rescue without assistance because one of the mostdifficult tasks of erecting a ladder in a proper position relative to achair is to place the ladder in an upright position for engaging thehook with the cable.

In use, when it becomes necessary to evacuate a person from a chair of alift, the attendant removes the ladder from a pole 10 which supports theaerial cable, pulls the cord 50 with the ladder still in verticalposition, lowers the ladder to position the cable 11 in the groove 31,releases the cord and adjusts the ladder so that its rungs aresubstantially parallel to the front of the chair 12. If the person inthe chair is able to remove himself from the chair unassisted, theattendant remains at the base of the ladder until the person descends.

If the person in the chair is unable to remove himself from the chair,the attendant ascends the ladder, assists the person from the chair tothe ladder, and descends the ladder with the person.

Thereafter, the ladder hook is freed from the cable and the ladder isreturned to the hook on the support pole 10 for future use.

From the foregoing description, it will be apparent to persons skilledin the art that this invention has fulfilled all of the objects statedabove.

While only one embodiment of the invention has been shown in thedrawings it is to be understood that this disclosure is for the purposeof illustration only and that various changes in shape, proportion andarrangements of parts as well as the substitution of equivalent elementsfor those herein shown and described may be made without departing fromthe spirit and scope of the invention as set forth in the appendedclaims.

I claim:

1. A ladder for evacuating persons from a chair aerial cable lift whichincludes an aerial cable and a chair suspended therefrom with theforward end of its seat substantially normal to the longitudinalcenterline of the cable when viewed from the top, said laddercomprisrng,

a pair of rigid side rails,

a plurality of spaced rigid rungs extending transversely between saidside rails,

a hook which is substantially U-shaped in cross section,

an elongate hook support member having its upper end rigidly attached tosaid hook, and

means for rigidly and removably attaching the lower end of said hooksupport member to one side of at least one ladder rung,

said hook comprising an elongate outer end member and two spaced sidemembers which combine to form an elongate .groove adapted to receive thecable of a chair aerial cable lift, the longitudinal centerline of saidgroove extending substantially normal to the longitudinal centerlines ofthe rungs of the ladder when viewed from the top, whereby when thebottom of said groove is positioned upon a chair aerial cable the rungsof the ladder are posi-' tioned substantially normal to the longitudinalcenterline of the aerial cable when viewed from the top andsubstantially parallel to the forward end of the seat of a chairsuspended from the aerial cable.

2. A ladder according to claim 1 wherein the sides of said spaced sidemembers converge as they extend downwardly from said elongate outer endmember.

3. A ladder according to claim 1 wherein the inner faces of said sidemembers are spaced apart a substantially equal distance whereby saidgroove is substantially the same width throughout and said hook alsocomprises latch means for releasably closing said groove at a localityspaced below said elongate outer end member of the hook.

4. A ladder according to claim 3 wherein said latch means comprises anarm, one end of which is pivotally attached to one side member of thehook, a tooth member attached to the other end of said arm and normallyextending transversely of said groove to close it and an actuatingmember attached to the other end of said arm and extending in theoposite direction from said tooth member.

5. A ladder according to claim 4 which also comprises spring meanshaving one end attached to said actuating member and. the other endattached to said one side member of the hook for normally biasing saidtooth member to groove closing position.

6. A ladder accordingto claim 1 wherein said means for securing saidhook support member to a ladder rung comprises a pair of spaced U-shapedmembers one at either side of said hook support member, bridging saidrung and detachably secured to said hook support member and an elongateangle member extending transversely between said U-shaped members andpositioned adjacent to said rung.

7. A ladder according to claim 6 which also comprises a plate memberpositioned between said rung and the adjacent side of said hook supportmember, the apex of said angle member being positioned adjacent to saidplate member and said rung being positioned between the curved ends ofthe U-shaped members and the sides of the angle member.

8. A ladder according to claim 6 wherein the apex of said angle memberis positioned against the curved ends of said U-shaped member and thesides of the angle member are positioned against said rung.

9. A ladder according to claim 1 wherein said elongate outer end membercomprises a pair of semielliptical grooves, one at each end thereof.

1. A ladder for evacuating persons from a chair aerial cable lift whichincludes an aerial cable and a chair suspended therefrom with theforward end of its seat substantially normal to the longitudinalcenterline of the cable when viewed from the top, said laddercomprising, a pair of rigid side rails, a plurality of spaced rigidrungs extending transversely between said side rails, a hook which issubstantially U-shaped in cross section, an elongate hook support memberhaving its upper end rigidly attached to said hook, and means forrigidly and removably attaching the lower end of said hook supportmember to one side of at least one ladder rung, said hook comprising anelongate outer end member and two spaced side members which combine toform an elongate groove adapted to receive the cable of a chair aerialcable lift, the longitudinal centerline of said groove extendingsubstantially normal to the longitudinal centerlines of the rungs of theladder when viewed from the top, whereby when the bottom of said grooveis positioned upon a chair aerial cable the rungs of the ladder arepositioned substantially normal to the longitudinal centerline of theaerial cable when viewed from the top and substantially parallel to theforward end of the seat of a chair suspended from the aerial cable.
 2. Aladder according to claim 1 wherein the sides of said spaced sidemembers converge as they extend downwardly from said elongate outer endmember.
 3. A ladder according to claim 1 wherein the inner faces of saidside members are spaced apart a substantially equal distance wherebysaid groove is substantially the same width throughout and said hookalso comprises latch means for releasably closing said groove at alocality spaced below said elongate outer end member of the hook.
 4. Aladder according to claim 3 wherein said latch means comprises an arm,one end of which is pivotally attached to one side member of the hook, atooth member attached to the other end of said arm and normallyextending transversely of said groove to close it and an actuatingmember attached to the other end of said arm and extending in theoposite direction from said tooth member.
 5. A ladder according to claim4 which also comprises spring means having one end attached to saidactuating memBer and the other end attached to said one side member ofthe hook for normally biasing said tooth member to groove closingposition.
 6. A ladder according to claim 1 wherein said means forsecuring said hook support member to a ladder rung comprises a pair ofspaced U-shaped members one at either side of said hook support member,bridging said rung and detachably secured to said hook support memberand an elongate angle member extending transversely between saidU-shaped members and positioned adjacent to said rung.
 7. A ladderaccording to claim 6 which also comprises a plate member positionedbetween said rung and the adjacent side of said hook support member, theapex of said angle member being positioned adjacent to said plate memberand said rung being positioned between the curved ends of the U-shapedmembers and the sides of the angle member.
 8. A ladder according toclaim 6 wherein the apex of said angle member is positioned against thecurved ends of said U-shaped member and the sides of the angle memberare positioned against said rung.
 9. A ladder according to claim 1wherein said elongate outer end member comprises a pair ofsemi-elliptical grooves, one at each end thereof.